Numerical index of the discriminatory ability of typing systems: an application of Simpson''s index of diversity.

An index of discrimination for typing methods is described, based on the probability of two unrelated strains being characterized as the same type. This index may be used to compare typing methods and select the most discriminatory system.     

A comparison of the Fishbein and Ajzen and the Triandis attitudinal models for the prediction of exercise intention and behavior

The main purpose of the study was to compare the efficiency of the Fishbein and Ajzen and the Triandis models to predict (1) the intention to participate regularly in some physical activities during free time within a 3-week period and (2) the exercise behavior within these 3 weeks among a group of 166 subjects, aged 22 to 65 years. Our results show that the Triandis model was as efficient as the Fishbein and Ajzen model in predicting the exercise behavior. However, the results obtained from the Triandis model demonstrate the importance of the habit of exercising in predicting the exercise behavior. Moreover, the Triandis model was superior to the Fishbein and Ajzen model in explaining behavioral intention. Of particular interest was the salience of the affective, social, and personal belief components of the Triandis model. In addition, from a practical perspective, this comparative study showed that (1) to exercise regularly is perceived as hard work, and (2) individuals believe that it is their own responsibility to exercise or not to exercise.     

Acid-base equilibrium in exhaled breath condensate of allergic asthmatic children

BACKGROUND: The dysregulation of airway pH control may have a role in asthma pathophysiology. The measurement of exhaled breath condensate (EBC) pH and ammonia levels may be used as a noninvasive method to study acid-base status in the airway of asthmatics. METHODS: Exhaled breath condensate from 29 allergic stable asthmatic children and 13 healthy controls was collected by cooling exhaled air during tidal breathing. Ammonia was measured by high-performance liquid chromatography with fluorescence detection. pH was measured after deaeration of EBC samples by bubbling with argon. The children also underwent FENO measurement. RESULTS: Both pH and ammonia values in EBC were significantly lower in the asthmatics than in the control group [pH: ICS-treated (median and interquartile range) 7.70 (7.62-7.74), steroid-naive 7.53 (7.41-7.68), controls 7.85 (7.80-7.90), P <0.01 and P <0.001, respectively; ammonia: ICS-treated 476.17 microM (282.50-594.80), steroid-naive 253.24 microM (173.43-416.08), controls 788.30 microM (587.29-1310.39), P < 0.05 and P <0.001, respectively]. Both pH and ammonia values were higher in ICS-treated than in steroid-naive asthmatic children. There was a significant correlation between EBC pH and ammonia concentrations. CONCLUSIONS: These data show that EBC pH values of stable asthmatic children are lower compared with those of healthy controls and positively correlated with ammonia concentrations, supporting the hypothesis that airway acidification may have a role in the pathobiology of allergic asthma.     

Cytotoxic T cell recognition of Epstein-Barr virus-infected B cells. III. Establishment of HLA-restricted cytotoxic T cell lines using interleukin 2

Epstein-Barr virus (EBV)-specific cytotoxic T cell precursors, present in the circulation of previously infected (seropositive) individuals, have been reactivated in vitro by challenging with autologous EBV-transformed cells, and the reactivated populations subsequently expanded as interleukin 2 (IL2)-dependent cell lines. These lines were dominated by T cells possessing the cytotoxic/suppressor cell surface phenotype and, when tested for effector function in chromium-release assays, demonstrated potent EBV-specific, HLA-A and -B antigen-restricted cytotoxicity even when derived from seropositive donors whose initial cytotoxic response to in vitro reactivation was relatively weak. With all the lines tested from 10 seropositive donors, strong killing of autologous EBV-transformed cells was observed in the absence of any significant lysis of autologous mitogen-stimulated lymphoblasts or of a panel of EBV genome-negative cell lines sensitive to natural killing. Furthermore, the availability of IL2-expanded effectors cell populations allowed their being tested upon a wide panel of allogeneic EBV-transformed targets such that the dominant HLA-restricted reactivities within these populations could be identified. Monoclonal antibody blocking experiments confirmed that lysis of the autologous EBV-transformed cell line by IL2-expanded effectors could be specifically inhibited (a) by pretreatment of the target cells with antibodies binding to the HLA/beta 2-microglobulin complex, and (b) by pretreatment of the effector cells with the cytotoxic/suppressor T cell-specific antibody Leu 2a.     

The normal vascularization of the intradural filum terminale in man

Summary The arterial and venous blood-supply of the intradural filum terminale was studied microscopically in 18 fresh cadavers after removing the dorsolumbar spinal cord in one piece, with the roots and the filum in their dural sheath. The arteries were examined after manual injection of the artery of the lumbar enlargement, while study of the veins was made without injection since their bluish-black color made them easily identifiable. After gross examination, each specimen was fixed and then sectioned at 12 different levels from the medullary conus to the bottom of the dural sac for histologic study. The distribution of the vascularization the filum terminale appeared constant. A single artery, the artery of the filum, arises from the termination of the anterior spinal axis, either by trifurcation or from the proximal part of one of the 2 branches of the anastomotic ansa of the conus. The artery travels in front of the filum, with rapidly diminishing caliber; rarely, it can be followed into the sacral canal. The vein of the filum travels in front of that structure but behind the artery, as in the cord; its caliber is uniform but varies from subject to subject. It traverses the dura below and continuous with the anterior spinal vein above. No vessels were found on the dorsal aspect of the filum. While the artery of the filum is of a caliber proportional to that of the filum and appears to be a nutrient vessel, the vein has a caliber unrelated to that of the filum and appears rather as an intradural drainage route continuous with the anterior spinal vein. Several cases of disease of the filum terminale confirm this anatomic appearance and also show that, because of the existing hyperpressure in the vein of the filum, the posterior spinal vein also shares in the drainage of the latter and that entire system may function in both ascending and descending directions.

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La vascularisation normale du filum terminale intradural chez l'homme

Résumé La vascularisation artérielle et veineuse du filum terminale intradural a été étudiée sur 18 cadavres frais, sous microscope, après prélèvement en monobloc de la moelle épinière dorso-lombaire, des racines et du filum dans leur étui dural. L'examen des artères a été fait après injection manuelle de l'artère du renflement lombaire, tandis que l'étude des veines s'est faite sans injection compte tenu d'une coloration bleu-noir spontanée qui les rendent aisément identifiables. Après étude macroscopique, chaque pièce a été fixée, puis coupée à 12 niveaux différents depuis le cône médullaire jusqu'au fond du cul-de-sac dure-mérien, pour étude histologique. La distribution de la vascularisation du FT apparaît constante. Une artère unique, l'artère du FT, naît de la terminaison de l'axe spinal antérieur, soit par trifurcation, soit de la partie proximale d'une des 2 branches de l'anse anastomotique du cône. L'artère chemine devant le FT; son calibre diminue rapidement; rarement, elle a pu être suivie jusque dans le canal sacré. Une veine, la veine du FT, chemine en avant du FT mais en arrière de l'artère, comme au niveau médullaire. Son calibre est uniforme mais variable d'un sujet à l'autre. Elle traverse la dure-mère en bas; elle se continue avec la veine spinale antérieure en haut. Aucun vaisseau n'a été retrouvé à la face dorsale du FT. Si l'artère du FT a un calibre qui est proportionnel à celui du filum et apparaît comme un vaisseau nourricier, la veine a un calibre sans aucun rapport avec le volume de celui-ci et apparaît davantage comme une voie de drainage intradural en continuité avec la veine spinale antérieure. Quelques cas de pathologie du FT confirment cet aspect anatomique et montrent aussi qu'en raison de l'hyperpression veineuse régnant dans la veine du FT, la veine spinale postérieure participe également au drainage de celle-ci et que l'ensemble peut fonctionner dans les 2 sens ascendant ou descendant.

     

A critical review of health-related economic evaluations in Australia: implications for health policy

In Australia, as in many other countries, economic evaluation is increasingly seen by health care policy makers as a useful aid to priority setting and resource allocation. In Australia, economic evaluation is now a requirement for new drugs to be listed on the Pharmaceutical Benefits Scheme which provides a government subsidy on the price of listed drugs for purchasers. Yet, despite recognition of the importance of economic evaluation by policy makers, there is a paucity of published evaluations in Australia. We reviewed all of the 33 health-related economic evaluations conducted in Australia and subsequently published since 1978. This study assesses how well informed decision makers might be if they used the results and conclusions of published economic evaluations as an aid to resource allocation. The review highlights several issues: (i) it is difficult to interpret the conclusions or assess the generalisability of individual papers without information on the context of the original study; (ii) the choice of comparator(s) was often unexplained and most papers did not employ marginal analysis; (iii) in the absence of marginal analysis, the comparability of cost-effectiveness ratios in league tables must be questioned as well as the completeness (were all the relevant alternatives included?) of studies; and (iv) the quality of effectiveness evidence varies enormously, with some authors content to use the best available evidence (even if it is of poor quality). The development of standards for economic evaluation methods might ensure a more consistent and scientific approach to evaluative work, but they cannot guarantee it. A more concerted effort to disseminate the principles and methods of economic evaluation to policy makers and non-economist evaluators might be a more important precursor to improving the credibility and usefulness of economic evaluations in priority setting.     

Consensus statement on the live organ donor

The Authors for the Live Organ Donor Consensus Group

JAMA. 2000;284:2919-2926.

Objective  To recommend practice guidelines for transplant physicians, primary care providers, health care planners, and all those who are concerned about the well-being of the live organ donor.

Participants  An executive group representing the National Kidney Foundation, and the American Societies of Transplantation, Transplant Surgeons, and Nephrology formed a steering committee of 12 members to evaluate current practices of living donor transplantation of the kidney, pancreas, liver, intestine, and lung. The steering committee subsequently assembled more than 100 representatives of the transplant community (physicians, nurses, ethicists, psychologists, lawyers, scientists, social workers, transplant recipients, and living donors) at a national conference held June 1-2, 2000, in Kansas City, Mo.

Consensus Process  Attendees participated in 7 assigned work groups. Three were organ specific (lung, liver, and kidney) and 4 were focused on social and ethical concerns (informed consent, donor source, psychosocial issues, and live organ donor registry). Work groups' deliberations were structured by a series of questions developed by the steering committee. Each work group presented its deliberations to an open plenary session of all attendees. This information was stored and shaped into a statement circulated electronically to all attendees for their comments, and finally approved by the steering committee for publication. The term consensus is not meant to convey universal agreement of the participants. The statement identifies issues of controversy; however, the wording of the entire statement is a consensus by approval of all attendees.

Conclusion  The person who gives consent to be a live organ donor should be competent, willing to donate, free from coercion, medically and psychosocially suitable, fully informed of the risks and benefits as a donor, and fully informed of the risks, benefits, and alternative treatment available to the recipient. The benefits to both donor and recipient must outweigh the risks associated with the donation and transplantation of the living donor organ.

     

An outbreak of shigellosis in a child care centre.

Outbreaks of shigellosis in child care are not commonly reported in Australia, however Shigella bacteria can easily spread in these settings. We report an outbreak of shigellosis in a child care centre and discuss the control measures implemented. This investigation identified 20 confirmed cases of Shigella sonnei biotype g and a further 47 probable cases in children and staff who attended a child care centre, and their household contacts. The investigation highlighted the importance of stringent control measures and protocols for dealing with outbreaks of Shigella and other enteric infections in the child care setting, and the importance of prompt notification by both doctors and child care centres, of suspected outbreaks.